Process of agglomerating fine ores of metalliferous products.



UNITED STATES PATENT OFFICE.

nnmonn annxammn rmircmLLE, uF NANTE'S, FRANCE, ASSIGNOR TO THE con- PORATION 0F METALLURGISCHE GESELLSCHAFT A. G.. OF

. MAIN. GERMANY.

PROCESS OF AGGLOMERATING FINE FRANKFORT-ON-THE:

ORES 0R METALIJFERO US PRODUCTS.

No Drawing.

dinand Heberlein, there is disclosed a method ofsintering fine ores or metalliferous products according to which the ore, mixed withfuel, is exposed to the action of a current of air, with the result, that the ore is reduced to sinter in consequence of the heat produced by the combustion of the fuel. When this method is employed, the major portion of the fine ore is in most cases sintered in the form of a homogeneous block, and only a relatively small percentores,2 especially age of the ore5 to 10 per cent.remains unsintered. It is. often possible to increase the proportionlof ,sintered material and to diminish the time occupied in treating a charge by adding waterto the mixture of ore and coal. In the working of certain certain kinds of pyrites residues, and dust-like products of the blast-furnace, the method above referred to, even when water is added, fails to accomplish re;

- tained sults which can be regarded as entirely satis-' of the mafactory, too high a percentage It Would terial remaining 'unsintered. appear, that leaves the ore looseand porous, and permits the air blast to sweep through the-porous;

mass with great force, thus preventing-til particles. ,1";

My present invention is designed to oh-f According to m imviate this defect. proved method of working, the mixture; of ore and fuel is moistened with a solution of a suitable salt hereinafter more particularly referred to. When a salt solution is employed, it is probable that the water -con-. in the mass is retained by thesalt until the combustion reaches the particular part afiectedf- It may liowever,'be that the salt exercises upon the loose particles a cementing effect,

blast.

the water quickly evaporates,

so that only a restricted. passage allowed for the passage of the air been found particularly advantageous for the purpose above referred to. Solutions of this salt are obtained in large quantities as refuse, as for example, in the; freeing of pyrites cindersfrom copper.. The employment of sulfate of iron has the further advantage that the agglomerate not only suffers no deterioration qualitatively, but is improved by reason of the salt being decomposed in' the refining process, the sulfurous acid escaping while ferric oxid remains.

can of course be formed in thematerial case of an iron'ore, sulfuric acid be added, sulfate of iron is produced in the mass, or sulfate of manganese, in the case of a manganese -ore. In like manner, alkali and employed. These salts are decomposable at sinterin temperatures,

The degree of concentration of the salt solution to be employed, as also the quantity to be added, is'readily determinable by experiment' in respect to each particular ore. Asa rule, it is expedient to employ highly quantity of the solution as to insure complete saturation ofthe mass. In the case of sulfate of iron solutions, 10 to 15 Baum have been found to yield good results. I Having now particularly described and ascertained the nature of my said invention and in whatimanner the same is to be perfor1ned,-I claim:

consisting preparing a moistened mixture of finely -diY. 1edt al-bearing material, .fuel a'nd a decomposable. at sintering temperature igniting the mixture,

tially as described.

2. In the process consisting in preparing a moistened mixture tering temperatures, igniting the mixture, and passing tially as described.

an air blast through it, substan'.

3. "In the process of sintering, the steps Specification of Letters Patent. t t May 12, 1914, Application filed October 4, 1910. Serial No. 585,226.

The employment of sulfate of iron has i -Instead of employing salt solutions, they itself, by adding a suitable acid. If, in the.

earthy alkali sulfate and chlorids may be concentrated solutions, and to use such a ,1. In the process of sintering, the steps and passing an air blast through it, substanv ofsintering, the steps of finely divided metal-bearing'i material, fuel, and a sulfate salt decomposable atsin its consisting in preparing a moistened. mixture of 'finely divided metal-bearing material, fuel and a sulfate of. ametal decom posable at sintering temperatures, igniting the mixture, and passing an air blast through it, substantially as described.

4:. In the process of sintering, the steps consisting in preparing a moistened mixture of finely divided metal-bearing material, fuel and sulfate of iron, igniting the mix ture, and passing an air blast through it, substantially as described.

5. In the process of sintering finely divided metal-bearing material, thestep consisting of passing an air blast through an' ignited mass of such material, having adjacent to the blast exit surfacea moistened mixture of the finely divided metal-bearing material, fuel, and a salt decomposable at sintering temperatures; substantially as described.

6. In the processof sintering a mixture of finely divided metal-bearing vmaterial and fuel by conducting a blast of air through the mixture after ignition, the method of preventing disturbance of the particles of the mixture by the airblast, which consists in binding the said particles with a sulfate salt meaoaa which consists inbinding the said particles with a solution of a sulfate of a metal decomposable at sintering temperatures, substantially as described.

8. In the process of sintering a mixture.

of finely divided metal-bearing material and fuel by conducting a blast of air through the mixture after ignition, the method of preventing disturbance of the particles of the mixture by the air blast, which consists in binding the said particles withla sulfate of iron solution, substantially as described;

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.=

EDMOND ALEXANDRE PRE'I'CEILLE. 

